The invention relates to a vehicle lamp capable of switching light distribution, and more particularly, to a vehicle lamp having a solenoid-type actuator for switching the light distribution.
One lamp for use as a vehicle lamp is configured such that a variable shade is disposed in the lamp to switch light distribution and the variable shade is driven to switch an area where light emitted from a light source is shielded. Also, an actuator having a motor as a driving source and an actuator having a solenoid as a driving source have been proposed as an actuator for driving the variable shade. JP 2004-342615 A (corresponding to U.S. Pat. No. 7,600,903) describes an example of the former one. JP 2007-213938 A describes an example of the latter one. Pros and cons of these actuators are described below. For example, the motor-type actuator can be configured to be small in size even if a driving force required to drive the variable shade is obtained. However, a current change that is caused when the motor is rotated or stopped generates electromagnetic wave noises, and the thus-generated electromagnetic wave noises might cause malfunction of an electronic device (particularly, an electronic control unit) mounted on a vehicle. On the other hand, the solenoid-type actuator does not generate such electromagnetic wave noises. However, in order to obtain the driving force required to drive the variable shade, it is necessary to increase a diameter and/or a shaft length of a coil making up the actuator or to increase the number of turns in the coil. As a result, the solenoid-type actuator becomes large as compared with the motor-type actuator.